Objective: To investigate the impact of cerebellopontine angle (CPA) masses on subjective and measured taste function.

Study design: Retrospective cross-sectional study.

Setting: Tertiary referral center.

Patients: Consecutive adult patients with untreated CPA masses.

Interventions: Gustatory function was psychophysically measured with Taste Strips (range, 0-16) on both sides of the tongue. Subjective taste complaints were assessed using a questionnaire.

Main outcome measures: Half-sided taste impairment (hemi-ageusia) was defined as side-to-side asymmetry ≥4 points with <9 points on the side of the CPA mass. We used the Koos classification for vestibular schwannomas (VS) and, in the case of facial nerve palsy, the House-Brackmann grading system.

Results: We included 135 patients (mean [standard deviation (SD)] age, 55.3 ± 14.1 yr; 62 males). The most common CPA mass was VS (77%). Overall, the measured taste function was lower on the affected compared with the healthy side of the tongue (mean score, 9.8 ± 3.3 versus 11 ± 2.9; p < 0.0001). Looking for clinically relevant one-sided taste impairment revealed 18 (13.3%) patients with hemi-ageusia, but only 4 (30.8%) of those subjectively complained of taste dysfunction. Regarding VS, Koos IV masses presented the lowest score on the affected side (mean score, 7.5 ± 3.7). Six patients presented with facial palsy. Having facial palsy did not result in a lower Taste Strips score (p = 0.23).

Conclusion: Before any CPA mass treatment, a measurable ipsilateral decrease in gustatory function is present in many patients. Most patients do not notice this preexisting taste impairment. From a medicolegal standpoint, this warrants consideration. To avoid postoperative claims regarding taste function, a preoperative assessment may be considered.